#include <fstream>
#include<climits>
using namespace std;
ifstream cin ("lca.in");
ofstream cout ("lca.out");
int arb[500010],jump[100010],start[100010],n,m,euler[100010],viz[100010],o,poz,key,where[100010],a,b;
void read ()
{ int q; viz[0]=INT_MAX;
    cin>>n>>m;
    for(int i=2;i<=n;i++)
    {
        cin>>q;
        jump[i]=start[q];
        start[q]=i;
        arb[i]=i;
    }
}
void dfs (int nod)
{ euler[++o]=nod;
    int x=start[nod];
    while(x)
    {
        if(viz[arb[x]]==0)
        { viz[arb[x]]=viz[nod]+1;
            dfs(arb[x]);
            euler[++o]=nod;
        } x=jump[x];
    }
}
void up_date (int st,int dr,int nod)
{
    if(st>=poz && dr<=poz)
        arb[nod]=key;
    else
    {
        int mij=(st+dr)/2;
        if(poz<=mij) up_date(st,mij,nod*2);
        else up_date(mij+1,dr,nod*2+1);
        if(viz[arb[nod*2]]<viz[arb[nod*2+1]]) arb[nod]=arb[nod*2]; else arb[nod]=arb[nod*2+1];
    }
}
void make_arbore ()
{
    for(int i=1;i<=n;i++) arb[i]=0;
    for(int i=1;i<=o;i++)
    { poz=i; key=euler[i]; if(where[euler[i]]==0) where[euler[i]]=i;
        up_date(1,o,1);
    }
}
int find_out (int st,int dr,int nod)
{
    if(a<=st && b>=dr)
        return arb[nod];
    int mij=(st+dr)/2,x1=0,x2=0;
    if(a<=mij) x1=find_out(st,mij,nod*2);
    if(b>mij) x2=find_out(mij+1,dr,nod*2+1);
    if(viz[x1]<viz[x2]) return x1;
     else  return x2;
}
void solve_here ()
{
    for(int i=1;i<=m;i++)
    {
         cin>>a>>b; a=where[a]; b=where[b];
         if(a>b) swap(a,b);
         cout<<find_out(1,o,1)<<"\n";
    }
}
int main()
{
    read();
    dfs(1);
    make_arbore();
    solve_here();
    cin.close();
    cout.close();
    return 0;
}